Faucets generally include a faucet valve stem which is turned to open and close a valve, and a handle assembly mounted on the valve stem to turn the stem. Almost all home faucet valve stems in the United States have a threaded hole in the top of the stem into which a screw can be turned to hold a faucet handle to the stem. However, a wide variety of stem peripheral surfaces are encountered on the top part of the stem, including those with a square cross section, those with a splined cross section, and those with a circular cross section on one side and a flat surface on the other, with stems of a particular peripheral type occurring in different sizes. It may be noted, however, that most stems have peripheral surfaces to be engaged, which are of uniform cross-sections along the height of the stem top part.
In the past, when a faucet handle had to be replaced, it was often necessary to obtain a particular one of a large number of handle types, which was specifically made for that type of valve stem. This required dealers to stock a large number of faucet handle types, which raised the cost to the buyer. To avoid the need to stock many handle types, a universal coupling has been widely used, with a square or other nonround periphery that fits into a corresponding handle cavity, and with a hole that receives a valve stem. A set screw on the coupling has a pointed end that is tightened against the valve stem. An important disadvantage of such coupling is that the pointed end of the set screw contacts a very limited area of the valve stem, and when there is slippage the pointed end cuts a circular groove in the stem. This not only ruins the connection of the handle to the valve stem, but permanently damages the valve stem.
More recently, universal faucet handle repair kits have been sold, which enable a handle to be attached to a wide variety of valve stems without danger of slippage or damage to the valve stem. The kit includes a handle with a cavity of square cross section and small adapters or spuds whose outside fits the handle cavity, but with each spud having a different hole which fits a different type of valve stem. U.S. Pat. No. 4,739,788 by Reback describes a kit of this type. Each kit requires about 12 different spuds to accommodate valve stems having a wide variety of different peripheral surfaces to be engaged. While each spud is relatively small and inexpensive, the need to manufacture and package a large number of spuds with each kit, of which all but one will be discarded, increases the cost of the kit. Also, the need for the repair man to carefully select that spud which best fits the valve stem, increases the time and effort required to replace a handle. A faucet handle assembly which could be mounted on almost all home faucet valve stems in a reliable connection therewith, without requiring a large number of disposable spuds and without requiring the repair man to determine the precise type of valve stem on which he is working, would be of considerable value.